In conventional bi-fuel systems, an internal combustion engine may alternatively be operated either with only a first fuel or with only a second fuel.
It may be desirable, such as, for example, in the field of automotive technology, not only to reduce the pollutant emission on the basis of the fuel choice, but also to extend the range of the vehicle on one tank filling. This range may be required to be large enough so as not to limit the mobility of the motor vehicle on the basis of an existing fuel-supply network.
For this purpose, an EXPO™ vehicle of the BMW AG company may be alternatively operated using fuel or pure hydrogen. The switchover between exclusive fuel operation and exclusive hydrogen operation may be implemented by the driver.
In exclusive hydrogen operation, CO2—, CO— and HC-emissions do not occur. Furthermore, the NOX emission may be greatly reduced. However, the number of service stations providing hydrogen may be few, such as, for example, in rural areas, so that the mobility of the vehicle in exclusive hydrogen operation may be limited as a result. In contrast, in exclusive gasoline operation, the existing comprehensive supply network may be utilized. However, in exclusive gasoline operation, the pollutant emission is considerably higher than in pure hydrogen operation.
U.S. Pat. No. 6,035,837 discusses a bi-fuel injection system for the alternative operation of an internal combustion engine with two fluid fuels. Here, too, the internal combustion engine is required to be operated using either one fuel or the other.